This invention relates to a RFID (Radio Frequency Identification) label in which information data wirelessly sent from outside can be stored or from which information data can be wirelessly read toward the outside, a method for producing the RFID label, a device for producing the RFID label, a sheet member used for the RFID label, and a cartridge that can be mounted on the producing device.
Conventionally, a data capturing system for capturing data about articles of commerce while using RFID labels, in each of which an IC chip or the like is embedded, is known as an example of a system in which data stored in such a RFID label is wirelessly exchanged (see Patent Document 1, for example).
For example, an electromagnetic induction method is applied to the RFID label used in the data capturing system. According to this method, when the RFID label attached to an article enters a magnetic field, an electromotive force is generated in a resonance circuit as a result of electromagnetic induction, and, based on the electromotive force, radio waves are emitted.
In this system, a reflected wave returned from the RFID label is received by a receptor, and, based on the reflected wave received thereby, data pre-stored in the RFID label can be remotely read. Therefore, this system can be used for various purposes of use.
If the fact that data has once been captured from the RFID label attached to the article is stored, it is possible to, for example, sound an alarm to the effect that the article has been unlawfully taken out without capturing data. For example, a bar code is printed on the RFID label. When articles of commerce are lawfully taken out, the bar code is scanned with a scanner so as to read and gather data, and, at the same time, radio waves are emitted from a transmitter mounted on the scanner. Its internal circuit is then short-circuited or opened so as to stop the operation of an IC chip embedded in the RFID label. As a result, it becomes possible to take out only an article from which data has been gathered. However, if an article to which a RFID label has been attached and which does not have the data storage of having gathered data is taken out, the IC chip responds to radio waves sent from the transmitter, i.e., from an interrogator, and emits a reflected wave. Therefore, it is judged that the article has been unlawfully taken out, and an alarm is sounded.
If the origin of an article, the production time or shipment time thereof, the kind thereof, the price thereof, etc., are wirelessly written and prestored onto the RFID label attached to the article, consumers can remotely obtain these pieces of information about each article.
According to a conventional technique, in order to form an image on a RFID label used in the thus operated system, for example, an IC chip known as a RFID chip and a RFID antenna conductor, which are RFID circuit elements, are first embedded in a band-shaped sheet member so as to form a RFID label, and then an image of, for example, a bar code is printed onto one surface of the RFID label.
[Patent Document 1] JP Patent No. 2843437
However, when put to practical use, the RFID label has still-unsolved problems concerning the printing of identification items attached to the label and concerning the IC chip and the antenna conductor embedded in the label.
For example, in order to attach an image to the RFID label, if the image is formed after forming the RFID label including an IC chip and other elements, the image will be distorted by the influence of the concavity and convexity of an image forming surface generated by the thickness of the IC chip or the other elements, or will become unclearly blurred by contact between the image forming surface and an object. Additionally, in a thermal method for forming an image by applying heat to an image forming surface, there is a possibility that, when the image is formed, heat applied to the RFID label will cause damage onto the resonance circuit and the IC chip contained in the RFID label or onto a joint part joining to the antenna conductor.
Additionally, when a sheet member used for the RFID label containing the IC chip, the antenna conductor, etc., is stored, the part of the IC chip or the antenna conductor is expanded in proportion to the thickness of the IC chip or the antenna conductor. Therefore, the sheet member has difficulty in maintaining a close contact state with another sheet member contiguous in the thickness direction when the sheet member is wound, and hence a gap or looseness will easily occur between the sheet members. If the sheet member for the RFID label is wound without reducing such a gap caused by the thickness of the IC chip or the antenna, the number of sheets that can be stored in a storage area will be lowered, and the frequency at which sheet members used for the RFID label are newly added will be heightened. If many labels are intended to be stored, the storage area will be enlarged, and hence the whole of a device for producing the RFID label must be enlarged. Additionally, there is a possibility that abrasion or the occurrence of static electricity caused by the friction occurring when the wound sheet members slip out of place will damage the IC chip, the antenna member, or at least one of the sheet members.
Additionally, although the RFID label is formed by arranging the IC chip and the antenna conductor connected thereto on one surface of the band-shaped sheet member, an area in which the IC chip and the other elements are disposed is partially thickened. Therefore, disadvantageously, for example, a cartridge requires a sufficient storage space for a band-shaped RFID label that is stored in a wound state like a roll and that has not yet been cut and for a short-piece-shaped RFID label that is stored in a cut state. The same applies to a label base material (sheet member) that has not yet been covered with a cover sheet.
In a RFID label producing device for producing the conventional RFID label in which the IC chip that has a RFID function and the RFID antenna conductor are embedded, the IC chip and the RFID antenna conductor each of which has a great thickness are embedded in the band-shaped sheet member, and hence the IC chip and the antenna conductor protrude from the sheet member. Therefore, the amount of protrusion of these elements is superposed when the band-shaped sheet member is wound like a roll. When this band-shaped sheet member (tag tape roll) is loaded into the device to produce a RFID label, the IC chip and the antenna conductor are pressed by a carrier roller in a label producing process. As a result, a load is imposed on the IC chip and the antenna conductor. Therefore, there is a fear that a circuit in the IC chip will be short-circuited, or a change in quality of the IC chip will bring about the loss of identification data stored in the IC chip, or the IC chip, the antenna conductor, and a joint part between the IC chip and the antenna conductor will be damaged. Additionally, there is a fear that, when the band-shaped sheet member from which an information discriminating portion that contains the antenna conductor and the IC chip protrudes is carried by the roller, the sheet member will be carried unstably and obliquely while being affected by a protruded part, or the feed speed will vary before and behind the protruded part in a process for performing a printing step on the band-shaped sheet member from which the information discriminating portion protrudes, so that printing defects, such as stains or shear in printing, occur.
Therefore, in consideration of the foregoing problems, it is a first object of the present invention to excellently maintain the state of an image printed on a RFID label used to wirelessly exchange data without damaging an IC chip and other elements embedded in the label when the label is produced. Additionally, with regard to keeping a sheet member used for the RFID label, it is a second object of the present invention to more efficiently put the sheet member without damaging the sheet member when the sheet member is loaded into a RFID label producing device. It is a third object of the present invention to provide a sheet member used for the RFID label that can reduce the whole of the RFID label member and that is spatially advantageous. It is a fourth object of the present invention to provide a RFID label producing device and a cartridge each of which has no fear that a circuit in an IC chip will be short-circuited, no fear that a change in quality of the IC chip will bring about the loss or crash of identification data, or no fear that a RFID antenna conductor or a joint part between the IC chip and the antenna conductor will be damaged.
On the other hand, a conventional tape printer (label producing device) has already been proposed in which a tape used as a material to be printed is loaded into a cartridge (cassette) in a rolled manner, is then drawn out from a roll so as to print desired characters onto the tape, and is discharged like a label (see Patent Document 2, for example).
In this conventional technique, two rolls are provided. One of them is a roll on which a base-material tape (double-faced adhesive tape) is wound, and the other is a roll on which a to-be-printed tape (film tape), onto which characters are printed and which is glued to the base-material tape, is wound. Predetermined characters are printed onto the to-be-printed tape while drawing out the base-material tape and the to-be-printed tape from the two rolls, respectively. Thereafter, the to-be-printed tape on which the characters have been printed and the base-material tape are glued together so as to produce a label.
At this time, a gluing adhesive layer to be glued onto the to-be-printed tape is provided on one side of a main tape part (base layer) of the base-material tape, whereas an affixing adhesive layer used to affix a produced label onto a specified object is provided on the opposite side of the main tape part. Further, the affixing adhesive layer is covered with a pattern sheet of paper that is peeled off when affixed. Therefore, a label formed by gluing the to-be-printed tape and the base-material tape together has a five-layer structure consisting of the to-be-printed tape layer, the gluing adhesive layer of the base-material tape, the base layer, the affixing adhesive layer, and the pattern sheet of paper.
[Patent Document 2] Japanese Published Unexamined Patent Application No. H7-314831 (see FIG. 1 and FIG. 2)
Referring to the tag mentioned above, if information, which is relative to RFID tag information stored in the IC chip but is independent of the RFID tag information, is printed on the label and is used, the related information can be visually checked from the side of users, and will serve the convenience of the users in various ways. Accordingly, a method can be proposed to produce a RFID label on which characters are printed and that contains a RFID circuit element by employing the conventional technique. In this method, the RFID circuit element is disposed in either the gluing adhesive layer or the affixing adhesive layer of the five-layer structure.
However, if the RFID circuit element is disposed in the affixing adhesive layer, an adhesive layer part that is closer to the pattern sheet than the RFID circuit element and that contributes substantially to affixing will be thinned (i.e., the quantity of adhesive will be reduced). As a result, there is a possibility that a sufficient adhesive force cannot be obtained in affixing. There is also a possibility that the RFID circuit element will be damaged since a reaction force that is generated by pressing and that is given from a surface to be affixed is easily applied onto the circuit element when affixed.
On the other hand, if the RFID circuit element is disposed in the gluing adhesive layer, an adhesive layer part that is closer to the to-be-printed tape than the RFID circuit element and that contributes substantially to gluing will be thinned (i.e., the quantity of adhesive will be reduced) in the same way as the above example. As a result, there is a possibility that a sufficient adhesive force cannot be obtained in gluing. There is also a possibility that the RFID circuit element will be damaged since a reaction force that is generated by pressing and that is given from a gluing means (a roller) is easily applied onto the circuit element when glued. Additionally, if the to-be-printed tape is transmissible (e.g., transparent or semitransparent), the RFID circuit element disposed in the gluing adhesive layer will be clearly seen (i.e., is exposed in appearance) from the side of the label surface beyond the to-be-printed tape. As a result, there arise disadvantages, such as externally undesirable matters or illegibleness.
A fifth object of the present invention is to provide a RFID label that can prevent a RFID circuit element from being damaged or being exposed in appearance when produced, a tag tape used to produce the RFID label, and a tag tape roll. According to the present invention, the RFID circuit element can be prevented from being damaged, and can avoid being exposed in appearance.